Leakage temperature dependency aware real-time scheduling for power and thermal optimization

Catering to society's demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. ^ In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research. ^

Real-time scheduling of embedded applications on multi-core platforms

For the past several decades, we have experienced the tremendous growth, in both scale and scope, of real-time embedded systems, thanks largely to the advances in IC technology. However, the traditional approach to get performance boost by increasing CPU frequency has been a way of past. Researchers from both industry and academia are turning their focus to multi-core architectures for continuous improvement of computing performance. In our research, we seek to develop efficient scheduling algorithms and analysis methods in the design of real-time embedded systems on multi-core platforms. Real-time systems are the ones with the response time as critical as the logical correctness of computational results. In addition, a variety of stringent constraints such as power/energy consumption, peak temperature and reliability are also imposed to these systems. Therefore, real-time scheduling plays a critical role in design of such computing systems at the system level. We started our research by addressing timing constraints for real-time applications on multi-core platforms, and developed both partitioned and semi-partitioned scheduling algorithms to schedule fixed priority, periodic, and hard real-time tasks on multi-core platforms. Then we extended our research by taking temperature constraints into consideration. We developed a closed-form solution to capture temperature dynamics for a given periodic voltage schedule on multi-core platforms, and also developed three methods to check the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research by incorporating the power/energy constraint with thermal awareness into our research problem. We investigated the energy estimation problem on multi-core platforms, and developed a computation efficient method to calculate the energy consumption for a given voltage schedule on a multi-core platform. In this dissertation, we present our research in details and demonstrate the effectiveness and efficiency of our approaches with extensive experimental results.

The framework for REVIEWS: an exploration into design principles for an electronic medical early warning system observation chart

The observation chart is for many health professionals (HPs) the primary source of objective information relating to the health of a patient. Information Systems (IS) research has demonstrated the positive impact of good interface design on decision making and it is logical that good observation chart design can positively impact healthcare decision making. Despite the potential for good observation chart design, there is a paucity of observation chart design literature, with the primary source of literature leveraging Human Computer Interaction (HCI) literature to design better charts. While this approach has been successful, this design approach introduces a gap between understanding of the tasks performed by HPs when using charts and the design features implemented in the chart. Good IS allow for the collection and manipulation of data so that it can be presented in a timely manner that support specific tasks. Good interface design should therefore consider the specific tasks being performed prior to designing the interface. This research adopts a Design Science Research (DSR) approach to formalise a framework of design principles that incorporates knowledge of the tasks performed by HPs when using observation charts and knowledge pertaining to visual representations of data and semiology of graphics. This research is presented in three phases, the initial two phases seek to discover and formalise design knowledge embedded in two situated observation charts: the paper-based NEWS chart developed by the Health Service Executive in Ireland and the electronically generated eNEWS chart developed by the Health Information Systems Research Centre in University College Cork. A comparative evaluation of each chart is also presented in the respective phases. Throughout each of these phases, tentative versions of a design framework for electronic vital sign observation charts are presented, with each subsequent iteration of the framework (versions Alpha, Beta, V0.1 and V1.0) representing a refinement of the design knowledge. The design framework will be named the framework for the Retrospective Evaluation of Vital Sign Information from Early Warning Systems (REVIEWS). Phase 3 of the research presents the deductive process for designing and implementing V0.1 of the framework, with evaluation of the instantiation allowing for the final iteration V1.0 of the framework. This study makes a number of contributions to academic research. First the research demonstrates that the cognitive tasks performed by nurses during clinical reasoning can be supported through good observation chart design. Secondly the research establishes the utility of electronic vital sign observation charts in terms of supporting the cognitive tasks performed by nurses during clinical reasoning. Third the framework for REVIEWS represents a comprehensive set of design principles which if applied to chart design will improve the usefulness of the chart in terms of supporting clinical reasoning. Fourth the electronic observation chart that emerges from this research is demonstrated to be significantly more useful than previously designed charts and represents a significant contribution to practice. Finally the research presents a research design that employs a combination of inductive and deductive design activities to iterate on the design of situated artefacts.

El consumo tradicional de los nuevos medios. Análisis de la usabilidad de las publicaciones autóctonas para tableta en el contexto universitario español y brasileño

Esta investigación aborda el consumo que los jóvenes universitarios de España y Brasil realizan de las publicaciones para tabletas. A través del estudio de seis casos –las revistas españolas Don, VisàVis y Quality Sport, y los vespertinos brasileños O Globo a Mais, de Río de Janeiro; Estadão Noite, de Sao Paulo; y Diário do Nordeste Plus, de Fortaleza– se aplica una metodología cualitativa, el test de usabilidad, para detectar qué aspectos ralentizan y entorpecen la navegación en las nuevas generaciones de usuarios de medios móviles. A pesar de la influencia de las revistas impresas en la configuración de las publicaciones para tableta, los datos muestran que el usuario necesita “entrenarse” para conocer unas opciones de interacción a veces poco intuitivas o para las que carece de la madurez visual necesaria. Por ello las publicaciones más sencillas obtienen los mejores resultados de usabilidad.

Sustainability Enhancement of a Turbine Vane Manufacturing Cell through Digital Simulation based Design

Modern manufacturing systems should satisfy emerging needs related to sustainable development. The design of sustainable manufacturing systems can be valuably supported by simulation, traditionally employed mainly for time and cost reduction. In this paper, a multi-purpose digital simulation approach is proposed to deal with sustainable manufacturing systems design through Discrete Event Simulation (DES) and 3D digital human modelling. DES models integrated with data on power consumption of the manufacturing equipment are utilized to simulate different scenarios with the aim to improve productivity as well as energy efficiency, avoiding resource and energy waste. 3D simulation based on digital human modelling is employed to assess human factors issues related to ergonomics and safety of manufacturing systems. The approach is implemented for the sustainability enhancement of a real manufacturing cell of the aerospace industry, automated by robotic deburring. Alternative scenarios are proposed and simulated, obtaining a significant improvement in terms of energy efficiency (−87%) for the new deburring cell, and a reduction of energy consumption around −69% for the coordinate measuring machine, with high potential annual energy cost savings and increased energy efficiency. Moreover, the simulation-based ergonomic assessment of human operator postures allows 25% improvement of the workcell ergonomic index.

Knowledge Workers and Associative Activity: An Examination of Knowledge Work Systems and Settings

Thesis (Ph.D.)--University of Washington, 2016-08

Exploring design patterns for sustainable behaviour

Products and services explicitly intended to influence users’ behaviour are increasingly being proposed to reduce environmental impact and for other areas of social benefit. Designing such interventions often involves adopting and adapting principles from other contexts where behaviour change has been studied. The ‘design pattern’ form, used in software engineering and HCI, and originally developed in architecture, offers benefits for this transposition process. This article introduces the Design with Intent toolkit, an idea generation method using a design pattern form to help designers address sustainable behaviour problems. The article also reports on exploratory workshops in which participants used the toolkit to generate concepts for redesigning everyday products—kettles, curtains, printers and bathroom sinks/taps—to reduce the environmental impact of use. The concepts are discussed, along with observations of how the toolkit was used by participants, suggesting usability improvements to incorporate in future versions.

Making instructions for others: exploring mental models through a simple exercise

This article introduces the idea of asking people to create instructions for others, as a way of exploring their mental models of designed systems. An example exercise run at the 2012 Brighton Maker Faire provides context. Article part of the 'On Modelling' forum edited by Hugh Dubberly.

Designing motivation or motivating design? Exploring Service Design, motivation and behavioural change

Motivation researcher Edward Deci has suggested that if we want behavioural change to be sustainable, we have to move past thinking of motivation as something that we ‘do’ to other people and see it rather as something that we as Service Designers can enable service users to ‘do’ by themselves. In this article, Fergus Bisset explores the ways in which Service Designers can create more motivating services. Dan Lockton then looks at where motivating behaviour via Service Design often starts, with the basic ‘pinball’ and ‘shortcut’ approaches. We conclude by proposing that if services are to be sustainable in the long term, we as Service Designers need to strive to accommodate humans' differing levels of motivation and encourage and support service users' sense of autonomy within the services we design.

Design for repair: empowering consumers to fix the future

By understanding how everyday devices work, individuals can – with the help of a growing online community – enjoy extending the life of products and drive socially responsible design.

Designing the Spectator Experience

Interaction is increasingly a public affair, taking place in our theatres, galleries, museums, exhibitions and on the city streets. This raises a new design challenge for HCI, questioning how a performer s interaction with a computer experienced is by spectators. We examine examples from art, performance and exhibition design, comparing them according to the extent to which they hide, partially reveal, transform, reveal or even amplify a performerts manipulations. We also examine the effects of these manipulations including movements, gestures and utterances that take place around direct input and output. This comparison reveals four broad design strategies: `secretive,' where manipulations and effects are largely hidden; `expressive,' where they are revealed, enabling the spectator to fully appreciate the performer's interaction; `magical,' where effects are revealed but the manipulations that caused them are hidden; and finally `suspenseful,' where manipulations are apparent, but effects only get revealed when the spectator takes their turn.

Trace Oblivious Program Execution

The big data era has dramatically transformed our lives; however, security incidents such as data breaches can put sensitive data (e.g. photos, identities, genomes) at risk. To protect users' data privacy, there is a growing interest in building secure cloud computing systems, which keep sensitive data inputs hidden, even from computation providers. Conceptually, secure cloud computing systems leverage cryptographic techniques (e.g., secure multiparty computation) and trusted hardware (e.g. secure processors) to instantiate a “secure” abstract machine consisting of a CPU and encrypted memory, so that an adversary cannot learn information through either the computation within the CPU or the data in the memory. Unfortunately, evidence has shown that side channels (e.g. memory accesses, timing, and termination) in such a “secure” abstract machine may potentially leak highly sensitive information, including cryptographic keys that form the root of trust for the secure systems. This thesis broadly expands the investigation of a research direction called trace oblivious computation, where programming language techniques are employed to prevent side channel information leakage. We demonstrate the feasibility of trace oblivious computation, by formalizing and building several systems, including GhostRider, which is a hardware-software co-design to provide a hardware-based trace oblivious computing solution, SCVM, which is an automatic RAM-model secure computation system, and ObliVM, which is a programming framework to facilitate programmers to develop applications. All of these systems enjoy formal security guarantees while demonstrating a better performance than prior systems, by one to several orders of magnitude.

Mission and Scenario Planning for Unmanned Aerial Vehicles (Path Planning and Collision Avoidance Systems)

As unmanned autonomous vehicles (UAVs) are being widely utilized in military and civil applications, concerns are growing about mission safety and how to integrate dierent phases of mission design. One important barrier to a coste ective and timely safety certication process for UAVs is the lack of a systematic approach for bridging the gap between understanding high-level commander/pilot intent and implementation of intent through low-level UAV behaviors. In this thesis we demonstrate an entire systems design process for a representative UAV mission, beginning from an operational concept and requirements and ending with a simulation framework for segments of the mission design, such as path planning and decision making in collision avoidance. In this thesis, we divided this complex system into sub-systems; path planning, collision detection and collision avoidance. We then developed software modules for each sub-system

Leakage Temperature Dependency Aware Real-Time Scheduling for Power and Thermal Optimization

Catering to society’s demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research.

Design of products to honor people post mortem

The cemeterial units, are places of social practices of everyday life and worship and the tomb where nostalgia can be externalized and the memory of the deceased revered. In Western societies we can find a category of artifacts meant to evoke the memory or honor the dead. In this paper we we mention three examples of products that enabled a reflection on the concepts that gave rise to their ways, and that risks to fit them into a new "material culture", in that it may have created a break with the traditional system codes and standards shared by companies, and its manifestations in relation to the physical creation of this category of products. This work offers a reflection on the Design Products.What probably makes it special is the field where it is located: the design of products in one post mortem memory. Usually made of granite rock or marble, have the form of plate or tablet, open book or rolled sheet. On one side have a photograph of the person who intend to honor and inscriptions. The thought of inherent design of this work put on one side the intricate set of emotions that this type of product can generate, and other components more affordable, and concerning the form, function and object interactions with users and with use environments. In the definition of the problem it was regarded as mandatory requirements: differentiation, added value and durability as key objectives.The first two should be manifested in the various components / product attributes. The aesthetic and material/structural durability of product necessarily imply the introduction of qualifying terms and quantitative weights, which positively influence the generation and evaluation of concepts based on the set of 10 principles for the project that originated a matrix as a tool to aid designing products. The concrete definition of a target audience was equally important. At this stage, the collaboration of other experts in the fields of psychology and sociology as disciplines with particular ability to understand individuals and social phenomena respectively was crucial. It was concluded that a product design to honor someone post mortem, should abandon the more traditional habits and customs to focus on identifying new audiences. Although at present it can be considered a niche market, it is believed that in the future may grow as well as their interest in this type of products.